The defintion fixes a missing include within dune-uggrid.

Set the correct FieldInfo size in vtktest

Closes #191

See merge request core/dune-grid!765

[UGGrid] Use std::size_t as loop counter

See merge request core/dune-grid!764

Recently, dune-uggrid has started to replace C arrays by FieldVectors
for storing point positions.  Therefore copying such positions
in dune-grid can now use the assignment operator of FieldVector
instead of hand-coded loops.  This makes the code shorter.  It also
saves a few unnecessary calls to UGGridRenumberer.

This fixes a few signed/unsigned warnings

[uggrid] Simplify domain creation

See merge request core/dune-grid!761

[bugfix][HierarchicSearch] private --> protected.

See merge request core/dune-grid!762

Recent versions of CreateBoundaryValueProblem simply allocated
an object of type STD_BVP (aka std_BoundaryValueProblem).

Therefore, don't call the method, and simply call 'new' instead.

Rather than by name.

All it does is a single assignment.  Instead of calling the method,
do the assignment directly.

This is one further reduction of the complexity of UGGrid setup.

It is not used in dune-uggrid anymore.

'void' is part of an old abstract interface, which only creates
unnecessary complexity for us.

Remove nobindings ci jobs since already in the default set

See merge request core/dune-grid!758

Use less allocations on UGGrid intersection geometries

See merge request core/dune-grid!753

Avoid storing coordinates on the heap by exploiting the fact that we only have
cubes and simplices up to 3D. When the number of corners is the same use an std::array, otherwise use a ReservedVector. This avoid many allocations during grid iteration.

The common case of an intersection is when it has only one face. For this case we use a variant that either holds one face, a vector of faces, or none. This way the common case is stored in the stack whereas the general case is still possible but needs dynamic allocation

There is no inherent need to store geometries in the heap. This changes the data layout to store them in the stack. Incidentally, this also moves coordinates into the geometries to avoid an extra allocation on the vector of coordinates.

replace std::result_of with std::invoke_result to make std20 compilation work

See merge request core/dune-grid!757

Is available since std17

Simplify UGGrid domain creation

Closes #188

See merge request core/dune-grid!755

Now that STD_BVP_Configure has a domain* argument, ADL is enough
to find the correct method in dune-uggrid, and the wrapper in
ugwrapper.hh is not needed anymore.

These two methods have been removed from dune-uggrid.  Instead
'domain' objects can be simply handled via new/delete.

The current code looks like it leaks to the 'domain' object,
but it probably did so before, too.  To be fixed in a
later commit.

Previously, the ConfigPtr variable stored a pointer to that method.
We don't use the extra flexibility offered by that, so let's simplify
the code and just call STD_BVP_Configure directly.

Include std headers

See merge request !752

Speed up `UGGridGeometry`

See merge request !750

In particular, we cache integrationElement, jacobianTransposed
and jacobianInverseTransposed.  This leads to speedup
for high-order methods on simplex grids.

The old implementation constructed a GeometryType object and asked
that whether it was a simplex.  Apparently this inlined badly.
The new implementation queries the UG-internal data structures
directly, which leads to a measurable performance gain.

Improve support with MSVC

See merge request !745

UGGrid has used an overly complicated way to compute the
integrationElement since practically forever.  Instead of computing
the determinant of the Jacobian of the geometry transformation,
it computed the inverse determinant of the inverse Jacobian.
This lead to a matrix inversion being performed at each call
that wasn't actually necessary.

This patch removes this pointless inversion.

The name should really point out that it is about the *inverse*
transformation.

The UGGrid code dates to before constexpr if existed, and uses
particular "pointless" casts to achieve a similar effect.
Replace some of these casts by constexpr if, which is much easier
to read.

The code is simplified further because UGGrid has recently started
to use FieldVector for point coordinates.  Therefore, componentwise
copying is not necessary anymore.